Calculus removing/retrieving device and method

A calculus retrieving device for retrieving calculus in a renal pelvis, the calculus retrieving device comprising:

• a ureteroscope positionable in a ureteral lumen of a ureter, the ureteroscope including an instrument lumen;
• an elongated member positionable in the instrument lumen of the ureteroscope and movable along the instrument lumen of the ureteroscope to advance the elongated member toward the renal pelvis, the elongated member being sized to be positioned in the renal pelvis, the elongated member including a lumen extending along a length of the elongated member, the lumen including an open distal end at a distal end of the elongated member, the elongated member possessing an inner surface;
• a tubular member movably positioned inside the elongated member to advance the tubular member to a position in which a distal-most end of the tubular member is positioned distally beyond a distal-most end of the elongated member, the tubular member possessing an outer surface, and including a lumen opening at a discharge nozzle located at a distal end of the tubular member;
• a space between the inner surface of the elongated member and the outer surface of the tubular member, the space being connectable to a first source of fluid;
• an expandable and contractable renal cover part fixed to the elongated member at a distal end portion of the elongated member, the renal cover part including an interior communicating with the space so that fluid from the first source enters the interior of the renal cover part when the renal cover part is positioned in the renal pelvis to expand the renal cover and cover one part of the renal pelvis while an other part of the renal pelvis containing the calculus is not covered by the renal cover part;
• and
• the lumen in the tubular member being connectable to a second source of fluid so that fluid from the second source is discharged from the lumen in the tubular member by way of the discharge nozzle and is introduced into the other part of the renal pelvis to move the calculus located in the other part of the renal pelvis.